vendredi 4 septembre 2015

This week, the Large Hadron Collider (LHC) was switched off for its second scheduled technical stop since starting to run at the new high energy of 6.5 teraelectronvolts (TeV) per beam. These regular stops allow engineers and technicians to maintain the machine and ensure that all its components are working well.

Large Hadron Collider (LHC). (Image: CERN)

"Lots of activities were planned for this technical stop," says Marzia Bernadini of the CERN Engineering department, who is responsible for coordinating and planning the works. "As well as many maintenance and consolidation tasks, this week's work focussed on two main tasks: installing four beam-gas vertex detectors at Point 4; and replacing more than 1000 electronic circuit boards in the accelerator's quench protection system (QPS).”

The job of the QPS is to monitor the LHC's superconducting magnets for tiny changes in voltage. These magnets steer the particle beams around the accelerator's 27-kilometre ring. These magnets operate at very low temperatures – 1.9 K or -271.3°C – and even a tiny amount of energy released for any reason inside a magnet can warm its superconducting materials to above the critical superconducting temperature, causing a loss of superconductivity. This is called a quench, and just one millijoule – the energy deposited by a 1-centime euro coin falling from 5 cm – is enough to provoke one. When this happens, the current has to be safely extracted in a very short time. Magnet protection in case of quenches is a crucial part of the design of the LHC’s magnetic system, and the electronic cards are in effect the eyes and ears of the quench protection system.

Image above: More than 1000 electronic cards that form part of the LHC's Quench Protection System were replaced this week (Image: CERN).

"We have many thousands of QPS electronic cards in the LHC," says Andrzej Siemko, who leads the Machine Protection and Electrical Integrity group in the CERN Technology department. "Some of these, used for the protection of the main dipole bus bars, are showing a higher sensitivity to radiation than expected, so they need to be replaced."

This sensitivity is a limiting factor for increasing the intensity of the beam in the LHC – the chips on the cards stop working when a certain number of bunches of protons are injected and accelerated to the top energy. Siemko stresses that there is no danger to the machine – the cards are one of three independent systems operating to monitor the electrical health of the magnet circuits. Keeping the system working, ensuring the redundancy for safety, is the main goal.

The team believes that the root of the problem lies with changes made during the long shutdown that ended earlier this year. Tests of certain connections required a minor modification to the cards so they were replaced with new ones. The immediate solution is therefore to replace the modified cards with the originals, which worked well during the LHC's first 3-year run.

The work involved not only the replacement of more than 1000 cards, but also a whole series of electrical quality and powering test afterwards. For the international team that tackled the job, safety was a top priority. "The most important thing is safety, followed by the quality of the work," technical coordinator Bruno Puccio told the engineers and technicians assembled at a recent planning meeting. "Take your time to do a quality job to allow a smooth restart for the LHC."

Note:

CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 22 Member States.

If you liked the first historic images of Pluto from NASA’s New Horizons spacecraft, you’ll love what’s to come.

Seven weeks after New Horizons sped past the Pluto system to study Pluto and its moons – previously unexplored worlds – the mission team will begin intensive downlinking of the tens of gigabits of data the spacecraft collected and stored on its digital recorders. The process moves into high gear on Saturday, Sept. 5, with the entire downlink taking about one year to complete.

“This is what we came for—these images, spectra and other data types that are going to help us understand the origin and the evolution of the Pluto system for the first time,” said New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute (SwRI) in Boulder, Colorado. “And what’s coming is not just the remaining 95 percent of the data that’s still aboard the spacecraft— it’s the best datasets, the highest-resolution images and spectra, the most important atmospheric datasets, and more. It’s a treasure trove. ”

Even moving at light speed, the radio signals from New Horizons containing data need more than 4 ½ hours to cover the 3 billion miles to reach Earth.

Image above: This close-up image of a region near Pluto’s equator captured by NASA’s New Horizons spacecraft on July 14, 2015 reveals a range of youthful mountains rising as high as 11,000 feet (3.4 kilometers) above the surface of the dwarf planet. This iconic image of the mountains, informally named Norgay Montes (Norgay Mountains) was captured about 1 ½ hours before New Horizons’ closest approach to Pluto, when the craft was 47,800 miles (77,000 kilometers) from the surface of the icy body. The image easily resolves structures smaller than a mile across. The highest resolution images of Pluto are still to come, with an intense data downlink phase commencing on Sept. 5, 2015. Image Credits: NASA-JHUAPL-SwRI.

As a flyby mission, New Horizons was designed to gather as much information as it could, as quickly as it could, as it sped past Pluto and its family of moons – then store its wealth of data to its digital recorders for later transmission to Earth. Since late July, New Horizons has only been sending back lower data-rate information collected by the energetic particle, solar wind and space dust instruments. The pace picks up considerably on Sept. 5 as it resumes sending flyby images and other data.

During the data downlink phase, the spacecraft transmits science and operations data to NASA’s Deep Space Network (DSN) of antenna stations, which also provide services to other missions, like Voyager. The spacecraft’s distance from Earth slows communication rates, especially compared to rates offered by today’s high-speed Internet providers. With New Horizons past Pluto, the typical downlink rate is approximately 1-4 kilobits per second, depending on how the data is sent and which DSN antenna is receiving it.

“The New Horizons mission has required patience for many years, but from the small amount of data we saw around the Pluto flyby, we know the results to come will be well worth the wait,” said Hal Weaver, New Horizons project scientist from the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.

Images above: All communications with New Horizons – from sending commands to the spacecraft, to downlinking all of the science data from the historic Pluto encounter – happen through NASA’s Deep Space Network of antenna stations in (clockwise, from top left) Madrid, Spain; Goldstone, California, U.S.; and Canberra, Australia. Even traveling at the speed of light, radio signals from New Horizons need more than 4 ½ hours to travel the 3 billion miles between the spacecraft and Earth. Images Credits: NASA.

The team also plans to continue posting new, unprocessed pictures from the Long Range Reconnaissance Imager (LORRI) on the New Horizons project website each Friday. The images are available at http://pluto.jhuapl.edu/soc/Pluto-Encounter/index.php; the next LORRI set is scheduled for posting on Sept. 11.

New Horizons is part of NASA’s New Frontiers Program, managed by the agency’s Marshall Space Flight Center in Huntsville, Alabama. The Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, designed, built, and operates the New Horizons spacecraft and manages the mission for NASA’s Science Mission Directorate. SwRI leads the science mission, payload operations, and encounter science planning.

The RapidScat instrument that flies aboard the International Space Station measures surface wind speed and direction over ocean areas. On September 2, several sweeps over the Pacific Ocean provided a look at Typhoon Kilo in the northwestern Pacific Ocean, Hurricane Ignacio north of Hawaii, and Hurricane Jimena east of Ignacio and also in the Central Pacific Ocean.

ISS-RapidScat in action. Animation Credit: NASA

From 1500 to 1800 UTC (11 a.m. to 2 p.m. EDT) RapidScat passed over all
three storms in the Pacific. RapidScat data showed that the strongest
sustained winds in all three storms were concentrated around the centers
of circulation and were stronger than 30 meters per second (108 kph/67
mph).

The three swaths of data were made into this panorama by Doug Tyler of the RapidScat team at NASA's Jet Propulsion Laboratory, Pasadena, California.

Images above: ISS-RapidScat location on the International Space Station (ISS) and area of measurements. Images Credit: NASA.

The ISS-RapidScat scatterometer is a radar instrument that operates at the microwave wavelength of 13.4 gigahertz. It bounces microwaves off the ocean surface and measures the echo strength. Several views of the same sea surface during the overflight of the instrument provide radar return signals that can be turned into estimates of wind speed and direction.

This NASA/ESA Hubble Space Telescope image shows Messier 96, a spiral galaxy just over 35 million light-years away in the constellation of Leo (The Lion). It is of about the same mass and size as the Milky Way. It was first discovered by astronomer Pierre Méchain in 1781, and added to Charles Messier’s famous catalogue of astronomical objects just four days later.

The galaxy resembles a giant maelstrom of glowing gas, rippled with dark dust that swirls inwards towards the nucleus. Messier 96 is a very asymmetric galaxy; its dust and gas are unevenly spread throughout its weak spiral arms, and its core is not exactly at the galactic center. Its arms are also asymmetrical, thought to have been influenced by the gravitational pull of other galaxies within the same group as Messier 96.

This group, named the M96 Group, also includes the bright galaxies Messier 105 and Messier 95, as well as a number of smaller and fainter galaxies. It is the nearest group containing both bright spirals and a bright elliptical galaxy (Messier 105).

Hubble and the sunrise over Earth

For images and more information about the Hubble Space Telescope, visit:

Soyuz crew members Sergey Volkov of Roscosmos, Andreas Mogensen of ESA (European Space Agency) and Aidyn Aimbetov of the Kazakh Space Agency joined their Expedition 44 crewmates when the hatches between the Soyuz TMA-18M spacecraft and the International Space Station officially opened at 6:15 a.m. EDT. Expedition 44 Commander Gennady Padalka of Roscosmos, as well as Flight Engineers Scott Kelly and Kjell Lindgren of NASA, Flight Engineers Oleg Kononenko and Mikhail Kornienko of Roscosmos, and Kimiya Yui of the Japan Aerospace Exploration Agency (JAXA) welcomed the new crew members aboard their orbital home, marking the first time since 2013 that nine people have been aboard the orbiting laboratory.

Image above: An international crew of nine from the U.S.. Russia, Japan, Denmark and Kazakhstan will work together on the orbital laboratory until Sept. 11. Image Credit: NASA TV.

Expedition 45/Visiting Crew Docks to the Space Station

The crew will support several hundred experiments in biology, biotechnology, physical science and Earth science — research that impacts life on Earth.

Image above: Sept. 4, 2015: International Space Station Configuration. The Soyuz TMA-18M spacecraft is docked to the Poisk mini-research module. The Soyuz TMA-16M spacecraft is docked to the Zvezda service module. The ISS Progress 60 spacecraft is docked to the Pirs docking compartment. The Soyuz TMA-17M spacecraft is docked to the Rassvet mini-research module. Japan’s “Kounotori” HTV-5 is berthed to the Harmony module. Image Credit: NASA.

The trip enables Roscosmos to rotate a crew member and a Soyuz spacecraft. Volkov will remain aboard the station for the next six months, returning in March 2016 with one-year mission crew members Kelly and Kornienko in the Soyuz TMA-18M.

Expedition 45/Visiting Crew Welcomed Aboard the Space Station

Padalka, who launched in March with Kelly and Kornienko in the Soyuz TMA-16M, will return to Earth in that spacecraft on Sept. 11 with Mogensen and Aimbetov, leaving Kelly in command of Expedition 45. Lindgren, Kononenko and Yui will remain aboard the station until late December. Each Soyuz remains in orbit for about six months.

Hopping, tumbling and flipping over are not typical maneuvers you would expect from a spacecraft exploring other worlds. Traditional Mars rovers, for example, roll around on wheels, and they can't operate upside-down. But on a small body, such as an asteroid or a comet, the low-gravity conditions and rough surfaces make traditional driving all the more hazardous.

Enter Hedgehog: a new concept for a robot that is specifically designed to overcome the challenges of traversing small bodies. The project is being jointly developed by researchers at NASA's Jet Propulsion Laboratory in Pasadena, California; Stanford University in Stanford, California; and the Massachusetts Institute of Technology in Cambridge.

How to Explore the Surface of a Comet or Asteroid

"Hedgehog is a different kind of robot that would hop and tumble on the surface instead of rolling on wheels. It is shaped like a cube and can operate no matter which side it lands on," said Issa Nesnas, leader of the JPL team.

The basic concept is a cube with spikes that moves by spinning and braking internal flywheels. The spikes protect the robot's body from the terrain and act as feet while hopping and tumbling.

"The spikes could also house instruments such as thermal probes to take the temperature of the surface as the robot tumbles," Nesnas said.

Two Hedgehog prototypes -- one from Stanford and one from JPL -- were tested aboard NASA's C-9 aircraft for microgravity research in June 2015. During 180 parabolas, over the course of four flights, these robots demonstrated several types of maneuvers that would be useful for getting around on small bodies with reduced gravity. Researchers tested these maneuvers on different materials that mimic a wide range of surfaces: sandy, rough and rocky, slippery and icy, and soft and crumbly.

"We demonstrated for the first time our Hedgehog prototypes performing controlled hopping and tumbling in comet-like environments," said Robert Reid, lead engineer on the project at JPL.

Hedgehog's simplest maneuver is a "yaw," or a turn in place. After pointing itself in the right direction, Hedgehog can either hop long distances using one or two spikes or tumble short distances by rotating from one face to another. Hedgehog typically takes large hops toward a target of interest, followed by smaller tumbles as it gets closer.

Image above: NASA's C-9 aircraft for microgravity research gave two Hedgehog prototypes a ride in June 2015 to test their maneuvers. Image Credit: NASA.

During one of the experiments on the parabolic flights, the researchers confirmed that Hedgehog can also perform a "tornado" maneuver, in which the robot aggressively spins to launch itself from the surface. This maneuver could be used to escape from a sandy sinkhole or other situations in which the robot would otherwise be stuck.

The JPL Hedgehog prototype has eight spikes and three flywheels. It weighs about 11 pounds (5 kilograms) by itself, but the researchers envision that it could weigh more than 20 pounds (9 kilograms) with instruments such as cameras and spectrometers. The Stanford prototype is slightly smaller and lighter, and it has shorter spikes.

Both prototypes maneuver by spinning and stopping three internal flywheels using motors and brakes. The braking mechanisms differ between the two prototypes. JPL's version uses disc brakes, and Stanford's prototype uses friction belts to stop the flywheels abruptly.

"By controlling how you brake the flywheels, you can adjust Hedgehog's hopping angle. The idea was to test the two braking systems and understand their advantages and disadvantages," said Marco Pavone, leader of the Stanford team, who originally proposed Hedgehog with Nesnas in 2011.

"The geometry of the Hedgehog spikes has a great influence on its hopping trajectory. We have experimented with several spike configurations and found that a cube shape provides the best hopping performance. The cube structure is also easier to manufacture and package within a spacecraft," said Benjamin Hockman, lead engineer on the project at Stanford.

Animation above: The Hedgehog robot, designed to explore the surfaces of comets and asteroids, can perform a "tornado" maneuver to spin and launch itself from the surface. Animation Credit: NASA/JPL-Caltech/Stanford.

The researchers are currently working on Hedgehog's autonomy, trying to increase how much the robots can do by themselves without instructions from Earth. Their idea is that an orbiting mothership would relay signals to and from the robot, similar to how NASA's Mars rovers Curiosity and Opportunity communicate via satellites orbiting Mars. The mothership would also help the robots navigate and determine their positions.

The construction of a Hedgehog robot is relatively low-cost compared to a traditional rover, and several could be packaged together for flight, the researchers say. The mothership could release many robots at once or in stages, letting them spread out to make discoveries on a world never traversed before.

Hedgehog is currently in Phase II development through the NASA Innovative Advanced Concepts (NIAC) Program, and is led by Pavone. The flight development and testing were supported by NASA's Center Innovation Fund (CIF) and NASA's Flight Opportunities Program (FOP), which were led by Nesnas. NIAC, CIF and FOP are programs in NASA's Space Technology Mission Directorate, located at the agency's headquarters in Washington. JPL is managed by the California Institute of Technology for NASA. Stanford University, MIT and JPL collaborate on the project.

How A Community Of Entrepreneurs Based In Chile Did “Rocket Science” In A Hungarian Castle

Yes, you read that right. A bunch of entrepreneurs decided to get into Space Science and do a bootcamp, because that is what we know how to do. This is the story of what happened and the lessons we learned in the process.

What is Copernicus I?

Copernicus I is an Exosphere program focused on experiential learning in science and technology in aerospace engineering and related fields. The camp has been designed to provide an opportunity for students to collaborate with scientists, mathematicians, engineers, and economists in researching the technical and economic feasibility and developing a working virtual model of an endogenously-powered space elevator.

The venue: marvelous Chateau Bercel

The 3-week program at Chateau Bercel outside Budapest, Hungary was comprised of participants from diverse backgrounds in science, mathematics, engineering, and economics, ranging from recent high school graduates to professionals in academia and the aerospace industry. It took place from July 13th to 31st, 2015. I will go into more detail below.

The Copernicus Series

Skinner Layne talking about the Copernicus Series

Video above: Skinner Layne, Founder of Exosphere, talks about the Copernicus Series and Exosphere’s view on Science and Technology.

Exosphere’s Copernicus Series brings Exosphere’s entrepreneurial and experience-oriented philosophy of learning to science and technology in the aerospace field and helps bridge the gap between research and business, breaking down the silos of knowledge that have been built up in modern society.

Among the goals of the Copernicus Series is to provide young people a hands-on learning experience that is directly connected to leading-edge research in science, which is usually only available to graduate and post-graduate students.

Why is this important? Worldwide demand for STEM educated professionals is growing rapidly but access to elite-level education at traditional learning institutions on a global level (I am aware of the postdoc problem in the US) remains limited to an elite few with the resources to pay for it. Online learning, blended learning, and micro-learning are part of a whole host of proposed answers floating around and while we encourage experimentation with all of them we take a non-ideological approach. Continuous experimentation with locally useful solutions is needed.

Exosphere’s thesis is that countless young people opt out of careers in science and technology because science education fails to expose them to the interesting applications of science to their life and the problems of the world. Furthermore, careers in science have come to be attached to a stigma concerning their earning potential, especially in traditional academia.

It is often years and years before students come in contact with actual applications of the skills and fields of the study they spend so much time acquiring. When they don’t develop a clear, experiential understanding of what, say, a physicist’s day to day work life looks like, it is no surprise that droves of STEM students change majors (~ 50 %) or abandon their studies entirely (~ 30 %) (though the lack of good employment opportunities is also a big factor). This can be counteracted by offering experiential learning opportunities before they start studies or during semester breaks. There those students curious about a particular field can sample it before committing years of their lives to it along with a pile of money in student loans tying them to risk-averse behaviour after graduation. Many of them are forced to take the first job they can find to start paying their installments.

The mission of Exosphere’s Copernicus Series is to expose youths to the exciting potential of science and prepare them for success in a quickly changing world, while helping experienced researchers commercialise and profit from their innovations through entrepreneurship. Through this process, the program will serve as an ongoing, productive platform for building the requisite brain trust of experts and practitioners in academia and industry to provide the resources and know-how necessary for further development of space related technology into commercializable endeavours while advancing space research and raising awareness for space exploration.

Why, oh why is science still not appealing to so many people who physically and mentally are fully able to engage in research and likely to make valuable contributions? One reason may just be the lack of excitement associated with not only the day to day work, but more importantly the public perception.

While we have made progress in making science more “sexy”, it still doesn’t hold the same appeal as entrepreneurship or programming. Both these areas champion a sort of “hacker mentality”, which is about overcoming limited resources, circumventing suffocating rules, combining old things in new and interesting ways, etc. All of these can, have been, and should apply to science, too.

Our slogan HACKING THE FINAL FRONTIER is about that: providing an experience along with a sexy public perception. Our participants should be proud to tell their friends about “this cool thing I went to in summer” instead of apologizing for “going to nerd camp”.

Another important feature of our programs is the mix of participants along a whole host of axes. This leads us directly into the lessons that I took away from the experiment of Copernicus I.

Diversity over Mastery

Discussing a simulation of Economic Development for the Space Elevator

Having people from many different backgrounds and of varying experience levels was both a challenge and an asset. Though every individual participant felt out of their depth a majority of the time, we advanced quickly through individual problems. Everybody got to learn things they wouldn’t have had an inclination or incentive to try and understand otherwise.

Let’s take a closer look at these axes of diversity and how they affected the program.

Age Distribution at Copernicus

Where the younger team members prodded the experts to explain their statements and justify their assumptions, the older ones helped co-curate the experience by channeling the work towards fruitful avenues.

Gender distribution at Copernicus

While many women from the Economic and Social Sciences applied, very few applied from the STEM fields. Only those women came to the program who were already working as professionals or entrepreneurs. We will continue to work on building an environment welcoming to our fellow female scientists and entrepreneurs.

One piece in this strategy is our Athena program for women in entrepreneurship and technology. The program is designed to offer ambitious and innovative women the opportunity to come together in a welcoming place, work and learn from each other, be inspired by successful international women visitors, and understand emerging technologies.

Curiously enough the women we did have at Copernicus were successful entrepreneurs in Tech and Space.

Occupation at Copernicus

3/4 of participants were pursuing degrees at traditional universities while the rest was split between paid employment and pursuing entrepreneurial ventures. Curiously enough two of the three women were entrepreneurs in space and tech, the other a consultant at Bain & Company. Copernicus II is going to be focused much more on building new ventures out of the findings at the program.

(If you are an entrepreneur or investor interested in space startups, drop me a line at moritz@exosphe.re).

Fields of Study represented at Copernicus

While most participants studied either Physics, Mathematics or Economics, there was a surprising level of diversity. Several people held several degrees or were working towards additional ones.

We even had one of the very few space lawyers present: Kamil Muzyka is the legal advisor to TRED Laboratories and extremely knowledgeable about the legal landscape in space exploration, asteroid mining, etc.

Educational Level at Copernicus

This counts only the highest level of formal education achieved. Multiple degrees and skill not certified by a university are not included. Many had additional knowledge in coding.

Country of Origin

Most participants were studying either in the US or the UK, but their nationalities covered 3/5 continents. Our notable guest from Japan was the lovely Kayoko Oshima, co-founder of the Japanese Space Elevator Association and principal at Jump To Space.

All in all a rather diverse group and by no means expertly knowledgeable in space elevator research. That is not necessary — though each and every participant did feel very much out of their depth a majority of the time, there was always somebody else to go to for a missing piece in the puzzle.

Experts are important, but only as resources to the participants. The depth of knowledge about a specific field is useful for speeding up the research done by participants, but it cannot replace it. Neither should it.

Going into the program we had a well defined schedule with quite a few theoretical sessions planned. With titles like “The Noumenia Process for the Lunar Elevator”, “The state of the art in Nanotechnology”, “Commercialisation of Space”, and “Space Colonization” we believed we had covered all our bases for getting everybody on the same page. Apparently too many bases…

Having lectures was good for building a common understanding of the problem and field, but it proved hindering in Week 2 when participants were dying to get to work. It reminded me of our very first entrepreneurship bootcamp, where we stayed too close to what you might call the “lecture model” we were trying to break away from. The theoretical part cannot take up more than 20 % and should be well fitted to the program. Though there are many interesting topics in space science, not all of them add value to a program that deals with a very specific problem like the endogenously-powered space elevator.

The lesson here is that having experts present is incredibly valuable, provided they spend more time helping the teams to refine the questions they’re investigating than presenting content in a one-way street. It’s the hard-won, hands-on expertise of many years spent in their respective fields that enables the participants to work through problems faster and close in on the right questions to ask in less time. There needs to be some structure so that people can work without having to worry about where to meet, when to eat, and so on. But this structure should always be amenable to change and stay in service of the goal, not become an impediment to work.

In a survey of NASA’s Hubble Space Telescope images of 2,753 young, blue star clusters in the neighboring Andromeda galaxy (M31), astronomers have found that M31 and our own galaxy have a similar percentage of newborn stars based on mass.

By nailing down what percentage of stars have a particular mass within a cluster, or the Initial Mass Function (IMF), scientists can better interpret the light from distant galaxies and understand the formation history of stars in our universe.

The intensive survey, assembled from 414 Hubble mosaic photographs of M31, was a unique collaboration between astronomers and “citizen scientists,” volunteers who provided invaluable help in analyzing the mountain of data from Hubble.

Image above: This Hubble mosaic of 414 photographs of the M31, or the Andromeda galaxy. On the bottom left is an enlargement of the boxed field (top) reveals myriad stars and numerous open star clusters as bright blue knots,spanning 4,400 light-years across. On the bottom right are six bright blue clusters extracted from the field. Each cluster square is 150 light-years across. Images Credits: NASA/ESA, J. Dalcanton, B.F. Williams, L.C. Johnson (Univ. of Washington), PHAT team, and R. Gendler.

“Given the sheer volume of Hubble images, our study of the IMF would not have been possible without the help of citizen scientists,” said Daniel Weisz of the University of Washington in Seattle. Weisz is lead author on a paper that appeared in the June 20 issue of The Astrophysical Journal.

Measuring the IMF was the primary driver behind Hubble’s ambitious panoramic survey of our neighboring galaxy, called the Panchromatic Hubble Andromeda Treasury (PHAT) program. Nearly 8,000 images of 117 million stars in the galaxy’s disk were obtained from viewing Andromeda in near-ultraviolet, visible, and near-infrared wavelengths.

Stars are born when a giant cloud of molecular hydrogen, dust and trace elements collapses. The cloud fragments into small knots of material that each precipitate hundreds of stars. The stars are not all created equally: their masses can range from 1/12th to a couple hundred times the mass of our sun.

M31: The Andromeda Galaxy. Images Credits: NASA/ESA/Hubble

Prior to Hubble’s landmark survey of the star-filled disk of M31, astronomers only had IMF measurements made in the local stellar neighborhood within our own galaxy. But Hubble’s bird’s-eye view of M31 allowed astronomers to compare the IMF among a larger-than-ever sampling of star clusters that are all at approximately the same distance from Earth, 2.5 million light-years. The survey is diverse because the clusters are scattered across the galaxy; they vary in mass by factors of 10, and they range in age from 4 to 24 million years old.

To the researchers’ surprise, the IMF was very similar among all the clusters surveyed. Nature apparently cooks up stars like batches of cookies, with a consistent distribution from massive blue supergiant stars to small red dwarf stars. “It’s hard to imagine that the IMF is so uniform across our neighboring galaxy given the complex physics of star formation,” Weisz said.

Curiously, the brightest and most massive stars in these clusters are 25 percent less abundant than predicted by previous research. Astronomers use the light from these brightest stars to weigh distant star clusters and galaxies and to measure how rapidly the clusters are forming stars. This result suggests that mass estimates using previous work were too low because they assumed that there were too few faint low-mass stars forming along with the bright massive stars.

Hubble orbiting Earth

This evidence also implies that the early universe did not have as many heavy elements for making planets, because there would be fewer supernovae from massive stars to manufacture heavy elements for planet building. It is critical to know the star-formation rate in the early universe—about 10 billion years ago—because that was the time when most of the universe’s stars formed.

The PHAT star cluster catalog, which forms the foundation of this study, was assembled with the help of 30,000 volunteers who sifted through the thousands of images taken by Hubble to search for star clusters.

The Andromeda Project is one of the many citizen science efforts hosted by the Zooniverse organization. Over the course of 25 days, the citizen scientist volunteers submitted 1.82 million individual image classifications based on how concentrated the stars were, their shapes, and how well the stars stood out from the background, which roughly represents 24 months of constant human attention. Scientists used these classifications to identify a sample of 2,753 star clusters, increasing the number of known clusters by a factor of six in the PHAT survey region. “The efforts of these citizen scientists opens the door to a variety of new and interesting scientific investigations, including this new measurement of the IMF,” Weisz said.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, in Washington.

For images and more information about PHAT and the Hubble Space Telescope, visit:

This rocky panoramic scene is the second picture of the Martian surface that was taken by Viking Lander 2 shortly after touchdown on Sept. 3, 1976 at 3:58 p.m. PDT (Earth received time). The site is on a northern plain of Mars, at about 48 N. Lat., 226 W. Long., known as Utopia Planitia. The picture sweeps around 330 degrees in azimuth, starting from northwest at the left through north (above the sampler arm housing) past east, where the sky is bright at the center, and southeast toward the right above the radioisotope thermoelectric generator cover.

Viking 2 Self-Portrait in color. Image Credits: NASA/JPL

The surface is strewn with rocks out to the horizon, ranging in size up to several meters across. Some pitted rocks resemble fragments of porous volcanic lava. Other rocks have grooves that may have been eroded by windblown sand and dust. Although fine-grained material is seen between the boulders, no sand dunes are evident. The dip in the eastern horizon at the center is an illusion caused by an 8-degree tilt of the Lander toward the west. Actually, the terrain is more level than that at the Viking 1 site.

The horizon toward the left of the panorama (northwest) appears featureless, indicating that it may be several kilometers distant. The sky at the center (east) is bright because the sun was above but out of the picture at 10 AM Mars time. Toward the right (southeast), the rocks that are silhouetted against the skyline indicate that the horizon is much nearer, probably because of a slight rise in that area of the terrain. The circular high-gain antenna at the right has clots of fine-grained material adhering to the lower half, some of which appeared to have been sliding downward while the camera was scanning the area. At the extreme right, the banded appearance resulted because the camera continued to scan while it was no longer moving in azimuth. Any motion or other variation in the scene would show up as a change in successive lines.

mercredi 2 septembre 2015

High above the thin Martian skies, NASA’s MAVEN spacecraft is carrying out a mission: determine how Mars lost its early atmosphere, and with it, its water. While previous Mars orbiters have peered down at the planet’s surface, MAVEN is spending part of its time gazing at the stars, looking for subtle changes in their color as they dip through the limb of Mars and set below the horizon.

Such stellar occultations reveal what Mars’ atmosphere is made of, and how its composition varies with altitude. MAVEN’s observations are providing scientists with the most detailed picture of the Mars upper atmosphere to date, helping them understand how a once-hospitable world changed into the forbidding desert that we see today.

A United Launch Alliance (ULA) Atlas V rocket carrying the fourth Mobile User Objective System satellite for the U. S. Navy launched from Space Launch Complex-41 at 6:18 a.m. EDT today. The MUOS-4 spacecraft will bring advanced, new, global communications capabilities to mobile military forces, as well as ensure continued mission capability of the existing Ultra High Frequency satellite communications system. This is ULA’s eighth launch in 2015, the second MUOS satellite launched in 2015 and ULA’s 99th successful launch since the company was formed in December 2006.

“The ULA team is proud to support the U.S. Navy and the U.S. Air Force by delivering this critical communications asset to orbit today,” said Jim Sponnick, ULA vice president, Atlas and Delta Programs. “Today’s successful launch will enable the MUOS constellation to reach global coverage. The Lockheed Martin-built MUOS-4 satellite will deliver voice, data, and video communications capability, similar to a cellular network, to our troops all over the globe.”

Atlas V MUOS-4 Launch Highlights

This mission was launched aboard an Atlas V Evolved Expendable Launch Vehicle (EELV) 551 configuration vehicle, which includes a 5-meter diameter payload fairing along with five Aerojet Rocketdyne solid rocket motors attached to the Atlas booster. The Atlas booster for this mission was powered by the RD AMROSS RD-180 engine and the Centaur upper stage was powered by the Aerojet Rocketdyne RL10C-1 engine.

The U.S. Navy’s MUOS is a next-generation narrowband tactical satellite communications system designed using a combination of orbiting satellites and relay ground stations to significantly improve communications for U.S. forces on the move. MUOS will provide new beyond-line-of-sight communications capabilities, with smartphone-like simultaneous voice, video and data – to connect military users almost anywhere around the globe.

MUOS satellite

ULA's next launch is the Atlas V Morelos-3, communications satellite for Lockheed Martin Commercial Launch Services and Secretaria de Comunicaciones y Transportes, a government agency of Mexico, scheduled for Oct. 2 from Space Launch Complex-41 at Cape Canaveral Air Force Station, Florida.

The EELV program was established by the U.S. Air Force to provide assured access to space for Department of Defense and other government payloads. The commercially developed EELV program supports the full range of government mission requirements, while delivering on schedule and providing significant cost savings over the heritage launch systems.

With more than a century of combined heritage, United Launch Alliance is the nation’s most experienced and reliable launch service provider. ULA has successfully delivered more than 95 satellites to orbit that provide critical capabilities for troops in the field, aid meteorologists in tracking severe weather, enable personal device-based GPS navigation and unlock the mysteries of our solar system.

Image above: The planet Saturn, viewed by NASA's Cassini spacecraft during its 2009 equinox. Data on how the rings cooled during this time provide insights about the nature of the ring particles. Image Credits: NASA/JPL/Space Science Institute.

When the sun set on Saturn's rings in August 2009, scientists on NASA's Cassini mission were watching closely. It was the equinox -- one of two times in the Saturnian year when the sun illuminates the planet's enormous ring system edge-on. The event provided an extraordinary opportunity for the orbiting Cassini spacecraft to observe short-lived changes in the rings that reveal details about their nature.

Like Earth, Saturn is tilted on its axis. Over the course of its 29-year-long orbit, the sun's rays move from north to south over the planet and its rings, and back again. The changing sunlight causes the temperature of the rings -- which are made of trillions of icy particles -- to vary from season to season. During equinox, which lasted only a few days, unusual shadows and wavy structures appeared and, as they sat in twilight for this brief period, the rings began to cool.

In a recent study published in the journal Icarus, a team of Cassini scientists reported that one section of the rings appears to have been running a slight fever during equinox. The higher-than-expected temperature provided a unique window into the interior structure of ring particles not usually available to scientists.

"For the most part, we can't learn much about what Saturn's ring particles are like deeper than 1 millimeter below the surface. But the fact that one part of the rings didn't cool as expected allowed us to model what they might be like on the inside," said Ryuji Morishima of NASA's Jet Propulsion Laboratory, Pasadena, California, who led the study.

The researchers examined data collected by Cassini's Composite Infrared Spectrometer during the year around equinox. The instrument essentially took the rings' temperature as they cooled. The scientists then compared the temperature data with computer models that attempt to describe the properties of ring particles on an individual scale.

What they found was puzzling. For most of the giant expanse of Saturn's rings, the models correctly predicted how the rings cooled as they fell into darkness. But one large section -- the outermost of the large, main rings, called the A ring -- was much warmer than the models predicted. The temperature spike was especially prominent in the middle of the A ring.

To address this curiosity, Morishima and colleagues performed a detailed investigation of how ring particles with different structures would warm up and cool down during Saturn's seasons. Previous studies based on Cassini data have shown Saturn's icy ring particles are fluffy on the outside, like fresh snow. This outer material, called regolith, is created over time, as tiny impacts pulverize the surface of each particle. The team's analysis suggested the best explanation for the A ring's equinox temperatures was for the ring to be composed largely of particles roughly 3 feet (1 meter) wide made of mostly solid ice, with only a thin coating of regolith.

"A high concentration of dense, solid ice chunks in this one region of Saturn's rings is unexpected," said Morishima. "Ring particles usually spread out and become evenly distributed on a timescale of about 100 million years."

The accumulation of dense ring particles in one place suggests that some process either placed the particles there in the recent geologic past or the particles are somehow being confined there. The researchers suggest a couple of possibilities to explain how this aggregation came to be. A moon may have existed at that location within the past hundred million years or so and was destroyed, perhaps by a giant impact. If so, debris from the breakup might not have had time to diffuse evenly throughout the ring. Alternatively, they posit that small, rubble-pile moonlets could be transporting the dense, icy particles as they migrate within the ring. The moonlets could disperse the icy chunks in the middle A ring as they break up there under the gravitational influence of Saturn and its larger moons.

"This particular result is fascinating because it suggests that the middle of Saturn's A ring may be much younger than the rest of the rings," said Linda Spilker, Cassini project scientist at JPL and a co-author of the study. "Other parts of the rings may be as old as Saturn itself."

During its final series of close orbits to Saturn, Cassini will directly measure the mass of the planet's main rings for the first time, using gravity science. Scientists will use the mass of the rings to place constraints on their age.

The Cassini-Huygens mission is a cooperative project of NASA, ESA and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate in Washington.

Mission managers for NASA's Soil Moisture Active Passive (SMAP) observatory have determined that its radar, one of the satellite’s two science instruments, can no longer return data. However, the mission, which was launched in January to map global soil moisture and detect whether soils are frozen or thawed, continues to produce high-quality science measurements supporting SMAP’s objectives with its radiometer instrument.

The SMAP mission is designed to help scientists understand the links between Earth's water, energy and carbon cycles and enhance our ability to monitor and predict natural hazards like floods and droughts. SMAP remains an important data source to aid Earth system modeling and studies. SMAP data have additional practical applications, including improved weather forecasting and crop yield predictions.

Image above: NASA’s SMAP mission, launched in January to map global soil moisture and detect whether soils are frozen or thawed, continues to produce high-quality science measurements with one of its two instruments. Image Credit: NASA.

The SMAP spacecraft continues normal operations and the first data release of soil moisture products is expected in late September.

"Although some of the planned applications of SMAP data will be impacted by the loss of the radar, the SMAP mission will continue to produce valuable science for important Earth system studies," said Dara Entekhabi, SMAP Science Team lead at the Massachusetts Institute of Technology in Cambridge.

On July 7, SMAP’s radar stopped transmitting due to an anomaly involving the radar's high-power amplifier (HPA). The HPA is designed to boost the power level of the radar's pulse to more than 500 watts, ensuring the energy scattered from Earth's surface can be accurately measured.

The SMAP project at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, formed an anomaly team to investigate the HPA issue and determine whether normal operation could be recovered. A series of diagnostic tests and procedures was performed on both the spacecraft and on the ground using flight spare parts.

Following an unsuccessful attempt on Aug. 24 to power up the radar unit, the project had exhausted all identified possible options for recovering nominal operation of the HPA and concluded the radar is likely not recoverable.

NASA has appointed a mishap investigation board to conduct a comprehensive review of the circumstances that led to the HPA anomaly in order to determine how the anomaly occurred and how such events can be prevented on future missions. JPL also will convene a separate failure review board that will work with the NASA investigation.

Animation above: NASA’s SMAP in action. Animation Credit: NASA.

SMAP was launched Jan. 31 and began its science mission in April, releasing its first global maps of soil moisture on April 21. To date, the mission has collected more than four months of science data, almost three months with the radar operating. SMAP scientists plan to release beta-quality soil moisture data products at the end of September, with validated data planned for release in April 2016.

SMAP's radar allowed the mission's soil moisture and freeze-thaw measurements to be resolved to smaller regions of Earth – about 5.6 miles (9 kilometers) for soil moisture and 1.9 miles (3 kilometers) for freeze-thaw. Without the radar, the mission's resolving power will be limited to regions of almost 25 miles (40 kilometers) for soil moisture and freeze-thaw. The mission will continue to meet its requirements for soil moisture accuracy and will produce global soil moisture maps every two to three days.

SMAP’s active radar and passive radiometer instruments are designed to complement each other and mitigate the limitations of each measurement alone. The radar enabled high-resolution measurements of up to 1.9 miles, but with lower accuracy for sensing surface soil moisture. In contrast, the microwave radiometer is more accurate in its measurements but has lower resolution of about 25 miles. By combining the active and passive measurements, SMAP was designed to estimate soil moisture at a resolution of 5.6 miles.

The nearly three months of coincident measurements by the two instruments are a first of their kind. The combined data set allows scientists to assess the benefit of this type of combined measurement approach for future missions. Scientists now are developing algorithms to produce a freeze-thaw data product at 25-mile resolution from the radiometer data. They also are evaluating whether the 25-mile radiometer soil moisture resolution can be improved.

Based on the available SMAP mission data, scientists have identified other useful science measurements that can be derived from the radiometer data, such as sea surface salinity and high winds over the ocean surface. Over the next several months, the SMAP project and NASA will work to determine how to implement these new measurements into the project's data products.

SMAP is managed for NASA's Science Mission Directorate in Washington by JPL, with instrument hardware and science contributions made by NASA's Goddard Space Flight Center in Greenbelt, Maryland. JPL built the spacecraft and is responsible for project management, system engineering, radar instrumentation, mission operations and the ground data system. Goddard is responsible for the radiometer instrument and science data products.